Diesel Detection in Surface Water in the Low ppb Range

A method for diesel detection in surface water in the low ppb range is presented. Even though standard commercial metal oxide gas sensors with detection limits in the ppm range are used, extraction of volatile compounds from the water enables a detection limit of about 2 ppb diesel in the water. The technique can be used for surface water monitoring. The standard technique of ultraviolet fluorescence detection has an interference problem with humic substances. This is not a problem with the suggested technique. Results from lab measurements as well as field tests at a water utility in the Stockholm region in Sweden are presented.